1. Field of the Invention
The present invention relates to a web winding apparatus for winding an elongate web cut to a predetermined width on a core, a method of and an apparatus for processing a web edge which is produced when a raw web is cut off, and a web processing apparatus for cutting an end of the elongate web to produce a web roll.
2. Description of the Related Art
Generally, winding machines for automatically winding an elongate web, e.g., an elongate film, on a core and cutting machines for cutting a wide raw film into an elongate film having a given width and automatically winding the elongate film on a core have various winding mechanisms for supporting the elongate film on the outer circumferential surface of the core when the core is rotated in a winding position.
Such winding mechanisms have a holder angularly movable for holding a spool on the tip end of a belt wrapper and a drive mechanism for reciprocally moving the belt wrapper until the central axis of the spool held by the holder is aligned with the central axis of a winding drum, as disclosed in Japanese patent publication No. 57-40052, for example.
Japanese utility model publication No. 48-38149 discloses a strip coiler having a mandrel for winding a strip into a coil, and a plurality of wrapper roll frames disposed around the mandrel with wrapper rolls and guide plates being positioned inwardly thereof, the wrapper roll frames each having an end pivotally mounted on a housing, and a plurality of fluid pressure cylinders coupled to the wrapper roll frames for pressing the wrapper rolls toward and retracting the wrapper rolls away from a position to start winding the strip.
It has become necessary in recent years to process various films of the same kind having different widths to meet demands for a variety of film products. Cutting machines and winding machines are thus required to have a winding mechanism capable of handling different widths of films.
For example, FIG. 93 of the accompanying drawings shows a winding mechanism 1 having two belt wrappers (or block wrappers) 4 for holding given portions of opposite ends of a core 3 which is supported by a core rotating mechanism 2, and a moving mechanism 5 for moving the belt wrappers 4 axially in the directions indicated by the arrow A depending on the axial length of the core 3. The moving mechanism 5 has a guide frame 6 extending in the directions indicated by the arrow A. The belt wrappers 4 are disposed on the guide frame 6 so as to be movable therealong by rack and pinion means (not shown) actuated by motors 7. The belt wrappers 4 are positioned in respective locations on the guide frame 6 depending on the axial length of the core 3, i.e., the width of a raw film.
However, since a film F is supported on the core 3 by the two belt wrappers 4, the film F cannot be held under pressure across its full width. Therefore, the film F wound around the core 3 tends to become loose or be displaced at its ends, and hence is not wound stably on the core 3.
One solution is to use a winding mechanism 1xe2x80x2 shown in FIG. 94 of the accompanying drawings. The winding mechanism 1xe2x80x2 has a plurality of block wrappers (or belt wrappers) 8 for holding the outer circumferential surface of a core 3 that is supported by a core rotating mechanism 2, and a moving mechanism 5xe2x80x2 for placing a given number of block wrappers 8 in a winding position depending on the axial length of the core 3. The moving mechanism 5xe2x80x2 has a guide frame 6xe2x80x2 extending in the directions indicated by the arrow A, with the block wrappers 8 being disposed on the guide frame 6xe2x80x2 so as to be movable therealong by motors 7xe2x80x2.
The winding mechanism 1xe2x80x2 is, however, problematic in that when a size change is performed in the transverse direction of a film F, those block wrappers 8 positioned in interference with the core rotating mechanism 2 need to be retracted into retracted zones 9xe2x80x2 outside of a raw film width 9, and hence the guide frame 6xe2x80x2 is considerably long in the directions indicated by the arrow A, making the winding mechanism 1xe2x80x2 large in overall size.
For changing the size of the core 3 and changing the direction in which the film F is wound, it is proposed to unitize the winding mechanism 1xe2x80x2 in its entirety and replace the unitized winding mechanism 1xe2x80x2 with another unit. However, since the winding mechanism 1xe2x80x2 is large in size, such unit replacement is difficult to perform.
If an actuator such as a cylinder or the like with a fixed stroke were used to move each of the block wrappers 8 in the directions indicated by the arrow A, then the winding mechanism 1xe2x80x2 could handle only films F of a particular size and would be poor in adaptability. For this reason, each of the block wrappers 8 uses a servomotor or a stepping motor as the positioning motor 7xe2x80x2, and hence needs a complex wiring and a complex control process.
To meet recent demands for a variety of film products, there have also been required two lines of film products, one having a film wound on a core with a coated surface of the film being directed toward the core, i.e., a roll with an inner coated surface, and the other having a film wound on a core with a coated surface of the film being directed away from the core, i.e., a roll with an outer coated surface. Therefore, various automatic winding apparatus capable of automatically changing the direction in which the film faces, i.e., the winding direction, are employed in the cutting and winding processes (see, for example, Japanese laid-open patent publication No. 10-25043 and Japanese laid-open patent publication No. 58-157663).
According to Japanese laid-open patent publication No. 10-25043, as shown in FIG. 95 of the accompanying drawings, two lock arms 3a, 3b swingable by respective cylinders 2a, 2b are disposed one on each side of a core 1a that is disposed in a film winding position. A rubber band 4a is trained around the lock arms 3a, 3b. A guide plate 7a for directing a film F which is fed vertically downwardly past a guide roller 5a selectively on both sides of the core 1a is swingably disposed above the core 1a. 
For winding the film F counterclockwise around the core 1a, the guide plate 7a is placed in the solid-line position in FIG. 95, and the lock arm 3b is held in an open position by the cylinder 2b. Therefore, the film F which is fed vertically downwardly past the guide roller 5a has its lading end guided by the guide plate 7a and enters between the core 1a and the lock arm 3b. Then, when the core 1a rotates counterclockwise in the direction indicated by the arrow, the leading end of the film F is introduced between the core 1a and the rubber band 4a, causing the film F to be wound around the core 1a. 
For winding the film F clockwise around the core 1a, the guide plate 7a is swung from the solid-line position to the dotted-line position, and the cylinders 2a, 2b are actuated to bring the lock arm 3a into an open position away from the core 1a and place the lock arm 3b in a closed position. The film F is now introduced between the core 1a and the rubber band 4a on the right side of the core 1a, and wound clockwise around the core 1a. 
However, since the film F that has been cut transversely travels along a tortuous path before the leading end of the film F enters between the rubber band 4a and the core 1a, or it is difficult to control the rubber band 4a, which serves as a belt wrapper, in the transverse direction of the film F, even if the position of the leading end of the film F that is paid out is accurately controlled, an edge Fa of the film F may possibly project from the end of the core 1a, as shown in FIG. 96 of the accompanying drawings, due to a meandering movement of the rubber band 4a. Consequently, the projecting edge Fa tends to be damaged when a roll made up of the film F wound around the core 1a is delivered to and packaged by a packaging process, or the packaged roll is shipped.
It has been desired to use various cores having different diameters including a 2-inch diameter and a 3-inch diameter and also having different widths covering various film widths. There is also a demand for the production of film rolls having films wound on such cores with both inner and outer coated surfaces.
According to the above conventional arrangements, though the direction in which the film faces or the winding direction can be changed, it is impossible to handle different outside diameters of cores and different film widths. Therefore, it is necessary to provide different automatic winding apparatus dedicated to handling various cores of different diameters and different axial lengths. As a result, a large facility is required for installing the different winding apparatuses, and the production cost is high.
Various proposals have heretofore been made to automatically wind an elongate film. One such proposal is a slitter apparatus disclosed in Japanese laid-open patent publication No. 6-234444, for example. In the conventional slitter apparatus, after a narrow web is wound to a given full length on a core disposed on the lower end of a core holding frame, producing a fully wound roll, a roll removal carriage is elevated to the core holding frame and supports the fully wound roll on its upper surface. The roll removal carriage removes the fully wound roll from the core holding frame, and is lowered while supporting the fully wound roll thereon.
When the core holding frame is moved and a new roll abuts against a touch roller, a cutting blade cuts off the narrow web in the transverse direction. Thereafter, one end of the cut-off narrow web is wound around the fully wound roll, and the other end is wound around the new core, starting to wind the narrow web around the new core.
When the roll removal carriage supports the fully wound roll, as shown in FIG. 97 of the accompanying drawings, a core rotating shaft 2c on a core holding frame 1b is rotated to wind a narrow web 4b to a given full length around a core 3c, producing a fully wound roll 5b. Thereafter, a roll removal carriage 6b is lifted to place the fully wound roll 5b thereon.
However, unless the narrow web 4b is wound to a certain length around the core 3c, the fully wound roll 5b is small in diameter, and when the roll removal carriage 6b is lifted, it may possibly interfere with the core holding frame 1b. Consequently, the fully wound roll 5b cannot be removed unless the fully wound roll 5b has a relatively large diameter, i.e., the narrow web 4b is substantially fully wound on the core 3c. 
Usually, the roll removal carriage 6b has a width equal to or smaller than the minimum width of the fully wound roll 5b so as to handle size changes of various fully wound rolls 5b having different widths. However, when a fully wound roll 5b having a maximum width is discharged, the roll removal carriage 6b may possibly be damaged because the surface pressure developed by contact between the roll removal carriage 6b and the fully wound roll 5b is high. In addition, a complex size changing structure is needed, resulting in the high cost of the facility.
In the winding process described above, unwanted film edges are cut off both sides of the raw film, and need to be efficiently processed. It is known to collect severed film edges with an air stream. However, wide film edges which have been cut off a raw film cannot be collected with an air stream. Another process is to use a chopper to cut film edges into small pieces. However, the use of the chopper is liable to increase the cost of the facility, and is likely to cause trouble due to electrostatic charges which may impede to achieve a desired edge processing capability.
Heretofore, it has been customary for a worker to process film edges manually. Specifically, after a film edge is wound around an edge shaft, the film edge is cut off by the worker using scissors. Then, the worker manually removes the film edge from the edge shaft, and discards the film edge into a trash box.
Since the film edge is processed in a dark room as the film needs to be shielded from light, it is difficult for the worker to use the scissors and carry the film edge which is heavy.
Wide film edges need to be processed highly frequently because there is a limitation, such as 147 N (Newton), for example, on weights that can be carried by workers. When such film edges are processed, since the production facility needs to be shut off, the overall process of processing films cannot be performed efficiently. In addition, it is not possible to reduce the cost of films by making the film edge processing unattended by workers.
It is a general object of the present invention to provide a web winding apparatus which is of a simple structure and is capable of winding an elongate film smoothly and highly accurately around a core.
A primary object of the present invention is to provide a web winding apparatus which is of a simple and compact structure and is capable of winding an elongate web smoothly and highly accurately around various cores having different axial lengths.
Another primary object of the present invention is to provide a web winding apparatus which is of a simple structure and is capable of automatically changing the direction in which a web faces, i.e., the winding direction, and of winding an elongate web highly accurately and efficiently around a core.
Still another primary object of the present invention is to provide a web winding apparatus which is of a simple structure and is capable of easily handling changes in the width and outside diameter of a roll for winding an elongate web efficiently.
Another primary object of the present invention is to provide a web winding apparatus which is of a simple and compact structure and is capable of winding an elongate web smoothly and highly accurately around various cores having different axial lengths in various directions in which the web faces or various winding directions.
A general object of the present invention is to provide a method of and an apparatus for processing a web edge efficiently in a short period of time with an effectively increased web processing capability.
Another general object of the present invention is to provide a web processing apparatus which is capable of winding a web around various cores having different axial lengths and different diameters in various directions in which the web faces or various winding directions for producing various web rolls smoothly and automatically.
The above and other objects, features, and advantages of the present invention will become more apparent from the following description when taken in conjunction with the accompanying drawings in which preferred embodiments of the present invention are shown by way of illustrative example.